The issue resolved itself on its own, thank you for trying to help.
I didn’t originally build this website and recently took over managing it. The people who built it didn’t leave any login credentials for Events Calendar Pro support so I haven’t been able to submit any tickets.
I’ve tried to change the template but that doesn’t seem to have any effect on it.
Thank you for your response!
The box next to “use updated calendar designs” is already checked.
As for the shortcode, I did deactivate several plugins while trying to fix the calendar so the shortcode is probably from one of those. I’ll have to do some more testing to find which one it is though.